Using Performance Manager; Performance Manager Readings - JBL VTX Series User Manual

14.2 USING PERFORMANCE MANAGER

When in the field, the Test System Mode in Performance Manager can be used to test an A8/B18 system. This test method is quick and
especially useful for determining whether all speaker cables, including cabinet-to-cabinet NL jumpers, are properly functioning.
To perform the test, Performance Manager uses the I-Tech HD's built-in noise generator in conjunction with the amplifier's current draw
and voltage sensing capabilities to generate a nominal load impedance reading for each amplifier output channel. Since broadband pink
noise is used as the test stimulus, the returned value is considered to be an impedance value, and it will differ from the DC resistance
values given earlier in this document.
STEPS:
• Make sure Performance Manager is online and connected to the devices.
• Navigate to the Test System Mode and make sure all the speakers are muted,
• Switch the Noise Generator to the ON position and change the level to a value between -30 dB and -10 dB. Values lower than-
30 dB may not be sufficient to trigger a reading.
• Unmute the speaker or a bandpass to start the measurement. The measured value is displayed on the speaker icons.

14.3 PERFORMANCE MANAGER READINGS

Below are the expected impedance values for circuits of B18 cabinets. The measurements below were taken at room temperature with
a cable length of 25 m (82 ft). Acceptable tolerance is +/- 0.5 Ω.
Variances in temperature, cable length, wire gauge, and usage, make the measurements recorded by Performance Manager more sus-
ceptible to drift. However, environmental variations like temperature are common across all similar circuits of a system. More important
than the individual component values is consistency across similar circuits. For example, all two-box circuits for an array should mea-
sure similarly. If one circuit differs by several ohms, there is likely something wrong with that specific circuit.
1 x VTX B18
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VTX B18 | User Manual
2 x VTX B18